SCALES OF NOTATION 21 50. Th. Every integer is divisible by unity, the quotient being the integer itself. In symbols:a >> 1 and a : 1 = a. 60. Th. Zero is divisible by every integer except itself, the quotient being zero. In symbols: If a —= 0, then 0 > a and 0 : a = 0. 61. Th. Ifb—= 0, then ab > b and (ab) : b = a. 62. Th. If a>> b and c—= 0, then ac = bc and (ac) : (bc) = a : b; conversely, if ac = bc, then a = b. 6. Th: ¢g=b—=b Fchn ik 64. Th. a>b~b=cDa>=c 65. Th. a>b~b>cDa>>c 66. Th. a>b—~c 3> dDue 00 67. Th. a>b~c=d~c—-=02Dac>bd 68. Th. a>c—~b rcDODatb e 69. Th. ¢ 3¢~ ecDo=00¢ 70. Th. a3 bD—a3b—~a> —-b~—a% =0 1. Th. a>b>Da=0~ |a| = |b| — |a] > |b] 72. Th. ¢ 3> b>Da=0~ |a|-< |b] 73. Th. a-=0~|a| < |b]| Da-—30 APPROXIMATE QUOTIENTS 74. Th. If a—>% b, it is possible to find two integers f, g such that fb is the greatest multiple of b less than a and gb the least multiple of b greater than a. Thus 4X6<25<5X6 5X (—6) < —25<4X(—6)